Results of surgical treatment for 33 intrathoracic recurrence after complete resection of non-small cell lung cancer were analyzed. Prognosis of the second surgical treatment were favorable in patients with subsequent cancer with in situ component and solitary lesion in lung parenchyma. Retrospective study of 53 patients who recurred and were thoroughly followed up their clinical course until lung cancer death revealed that the solitary one tends to be confined to the intrathoracic location, and the multiple one did not confined to the intrathoracic location but also extended to the extrathoracic distant metastasis or to the supraclavicular lymph nodes.